1. Field of the Invention
The present invention relates to a semiconductor integrated circuit used for fuses.
2. Background Art
In the prior art, electrical fuses provided in semiconductor integrated circuit include, for example, poly fuses (for example, see Mohsen Alavi, Mark Bohr, Jeff Hicks, Martin Denham, Allen Cassens, Dave Douglas, Min-Chun Tsai, “A PROM Element Based on Salicide Agglomeration of Poly Fuses in a CMOS Logic Process” Technical Digest of IEDM 1997, p. 855-858).
Such a poly fuse is programmed by, for example, a blowout caused by a predetermined current fed through a MOS transistor for writing.
During writing, the poly fuse is fed with a reading current by controlling a MOS transistor for reading which is connected to the poly fuse. After that, the value of current passing through the poly fuse or a current generated according to the state of the poly fuse is converted to a voltage, and the voltage is read as data.
In this way, the fuse (element) to be programmed and the MOS transistor for reading are separately provided.
Thus it is not possible to improve the degree of integration of circuits.